Liquid laundry detergent compositions are available in the form of water-soluble unit dose articles. Such water-soluble unit dose articles are preferred by consumers as they are convenient to use and reduce accidental spillage during detergent dosage in the wash operation.
Such water-soluble unit dose articles comprise a water-soluble film, preferably a polyvinylalcohol containing film that is formed into a pouch comprising an internal compartment. The liquid laundry detergent composition is comprised within the internal compartment such that the liquid laundry detergent composition is surrounded by the film and in contact with the film that forms the inner surface of the internal compartment.
Upon manufacture of the film, it has certain dissolution and tensile properties. Careful balance of the film plasticization properties are needed to ensure the film is not too ‘floppy’ affecting its dissolution characteristics in water, and not too brittle, leading to unwanted premature rupture of the unit dose article ahead of use. This plasticization of the film can be negatively affected by contact with the liquid detergent over time.
Therefore, there is a need for a liquid laundry detergent article whereby the plasticization properties of the film as manufactured are minimally affected by contact with the liquid detergent over time.
It was surprisingly found that the presence of 1,2-propanediol and dipropylene glycol in specific ratio to one another in the liquid laundry detergent composition addressed this technical problem.
It was further surprisingly found that careful balance of the ratio of anionic and nonionic surfactant in the presence of the 1,2-propanediol and dipropylene glycol provided improved stability of the liquid laundry detergent composition within the unit dose article.